JP5934985B2 - Solar cell module manufacturing method and solar cell module - Google Patents

Description

  The present invention relates to a method for manufacturing a solar cell module and a solar cell module manufactured thereby.

  As one of the conductor forming methods for solar cells, a method using a thermosetting conductive paste is known. In this case, the thermosetting conductive paste is applied to a substrate or the like by screen printing or the like, and is heat-treated at a temperature of about 100 ° C. to 300 ° C., so that the resin is cured and a conductive electrode is formed.

  In Patent Document 1, in a thermosetting conductive paste containing conductive particles and a resin, two or more kinds of conductive particles may be mixed and used, and the shape of the conductive particles may be spherical, flaky, or dendritic. Although there is no restriction | limiting, such as a shape and a fibrous form, it is said that powder particles are easy to contact each other and it is advantageous at an electroconductive point.

JP 2007-157434 A

  The connection between the solar cell and the connection electrode is ensured by balancing the adhesive strength between the solar cell and the connection electrode and the strength of the connection electrode itself.

  The method for manufacturing a solar cell module according to the present invention includes arranging a wiring material via an adhesive on a connection electrode of a solar cell, and pressing a crimping tool against the solar cell on which the wiring material is arranged with a predetermined pressure. The adhesive is heated to a curing temperature or higher and cured, and the predetermined crimping pressure of the crimping tool is such that the crimping pressure at the end of the solar cell along the longitudinal direction of the wiring material is greater than the crimping pressure at the center of the solar cell. Is also low.

  A solar cell module according to the present invention includes a solar cell having a connection electrode and a wiring material connected to the connection electrode via an adhesive, and the strength of the connection electrode itself is the length of the wiring material. The edge of the solar cell along the direction is weaker than the center of the solar cell.

  If the pressure bonding pressure when the wiring member is connected to the connection electrode via an adhesive is too high, peeling between the solar cell and the connection electrode tends to occur. With the above configuration, the connection between the solar cell and the connection electrode can be secured at the end of the solar cell, which is an important part for the connection between the solar cell and the wiring member.

It is a flowchart which shows the procedure of the manufacturing method of the solar cell module in embodiment of this invention. In FIG. 1, it is a figure which shows the process which forms the electrode for a connection of a solar cell with the electrically conductive paste which becomes a network structure by heating. In FIG. 1, it is a figure which shows the process which arrange | positions a wiring material. In FIG. 1, it is a figure which shows the process which sets a crimping | compression-bonding tool, presses with a predetermined crimping | compression-bonding pressure, and heats at predetermined temperature. In the process of FIG. 4, it is a figure which shows distribution of pressure bonding pressure. It is a figure which shows the other example which makes low the crimping | compression-bonding pressure of an edge part in the manufacturing method of the solar cell module in embodiment of this invention. It is a figure which shows the location where peeling can arise in the solar cell module of embodiment of this invention. In the solar cell module of embodiment of this invention, it is a figure which shows distribution of the ratio which the peeling mode between a solar cell and a connection electrode produces. It is a figure which shows the result of a peeling test when the crimping | compression-bonding pressure is made the same in the edge part and center part of a solar cell for the comparison. It is a figure which shows the result of a peeling test when using the method of FIG.

  Embodiments of the present invention will be described below in detail with reference to the drawings. The temperature, pressure stress, dimensions, and the like described below are illustrative examples, and can be appropriately changed according to the specifications of the solar cell module. Hereinafter, in all the drawings, one or the corresponding element is denoted by the same reference numeral, and redundant description is omitted.

  FIG. 1 is a flowchart showing a procedure of a method for manufacturing a solar cell module. 2 to 4 are diagrams for explaining each procedure in this flowchart.

  Since the solar cell module is formed by connecting a plurality of solar cells with a wiring material, a solar cell is prepared in order to manufacture the solar cell module. In order to prepare the solar cell, first, the photoelectric conversion unit 11 is formed (S10).

  2A and 2B are diagrams showing the solar cell 10, in which FIG. 2A is a plan view and FIG. 2B is a side view. The solar cell 10 includes a photoelectric conversion unit 11 that generates light-generated carriers of holes and electrons by receiving light such as sunlight. The solar cell 10 has, as main surfaces, a light receiving surface that is a surface on which light from the outside of the solar cell 10 is mainly incident and a back surface that is a surface opposite to the light receiving surface, but in the plan view of FIG. The light receiving surface is shown.

The photoelectric conversion unit 11 includes a substrate made of a semiconductor material such as crystalline silicon (c-Si), gallium arsenide (GaAs), indium phosphide (InP), for example. The structure of the photoelectric conversion unit 11 is a pn junction in a broad sense. For example, a heterojunction of an n-type single crystal silicon substrate and amorphous silicon can be used. In this case, an i-type amorphous silicon layer, a p-type amorphous silicon layer doped with boron (B) or the like, and indium oxide (In ₂ O ₃ ) translucency on the substrate on the light-receiving surface side. A transparent conductive film (TCO) 12 composed of a conductive oxide is stacked, and an i-type amorphous silicon layer and an n-type amorphous silicon layer doped with phosphorus (P) or the like are formed on the back side of the substrate, The transparent conductive film 13 can be laminated.

  The photoelectric conversion unit 11 may have a structure other than this as long as it has a function of converting light such as sunlight into electricity. For example, a structure including a p-type polycrystalline silicon substrate, an n-type diffusion layer formed on the light-receiving surface side, and an aluminum metal film formed on the back surface side may be used.

  Returning to FIG. 1, when the photoelectric conversion unit 11 is formed, the connection electrode 20 on the light receiving surface side is formed on the light receiving surface of the solar cell 10. The connection electrode 20 on the light receiving surface side is formed by printing a conductive paste in a predetermined pattern on the surface of the transparent conductive film 12.

  The conductive paste is obtained by mixing conductive particles into a resin using a solvent. There are various types of conductive pastes, which can be used properly according to the application. For example, a conductive paste in which conductive particles such as silver (Ag) are dispersed in a binder resin can be used. Here, the connection electrode 20 is formed using a sintered conductive paste that becomes a network structure by heating, as an improvement in conductivity (S11).

  The network structure is a structure in which conductive particles are fused to each other. For example, by heating a conductive paste containing conductive particles, the conductive particles can be fused together to form a network structure. In this embodiment mode, the network structure is a structure in which 50% or more of conductive particles observed under a microscope are fused to each other.

  The sintered conductive paste having a network structure by heating is obtained by mixing a plurality of spherical powders 21 with a resin such as an epoxy resin using a solvent. The spherical powder 21 is a substantially spherical conductive particle. When the conductive paste is heated, the spherical powders 21 are fused together to form a network structure. Due to this network structure, the conductivity of the connection electrode 20 is improved.

  The connection electrode 20 may include flakes in addition to the spherical powder 21. Flakes refer to conductive particles having a ratio of major axis to thickness of powder particles (major axis / thickness) ≧ 10 and an average particle diameter of about 2 to 5 μm or more. The flakes can be obtained, for example, by crushing the spherical powder 21 into a flat shape. Since the flakes have an action of dividing the network structure, the flakes have a function of relieving stress caused by fusion. The mixing ratio of the spherical powder 21 and the flakes can be determined based on the balance between the improvement of conductivity and stress relaxation.

  As the light receiving surface electrode provided for collecting the photogenerated carriers on the light receiving surface of the solar cell 10, a finger electrode is disposed in addition to the bus bar electrode serving as the connection electrode 20. In FIG. 2, the finger electrode is not shown.

  The finger electrode collects electricity from the entire light receiving surface, but is a thin wire electrode that is thinned so as to reduce the light shielding property. The finger electrode and the bus bar electrode are arranged orthogonally to each other and electrically connected. The width of the finger electrode is preferably about 30 μm to 150 μm, and the thickness is preferably about 10 μm to 80 μm. The interval between adjacent finger electrodes is preferably about 0.5 mm to 3 mm. The width of the bus bar electrode as the connection electrode 20 is preferably about 50 μm to 3 mm, and the thickness is preferably about 10 μm to 160 μm.

  Also on the back surface of the solar cell 10, the connection electrode 23 on the back surface side is formed on the surface of the transparent conductive film 13 on the back surface side of the photoelectric conversion unit 11. Similarly to the connection electrode 20 on the light-receiving surface side, the connection electrode 23 on the back surface side is also formed using a sintered conductive paste containing the spherical powder 21 and having a network structure by heating. Similarly to the light receiving surface side, the connection electrode 23 on the back surface side may further contain flakes in addition to the spherical powder 21.

  Returning to FIG. 1 again, next, the wiring material is arranged. As for the arrangement of the wiring material, the wiring material 25 is arranged on the connection electrode 20 on the light receiving surface side of the solar cell 10 via the adhesive 24, and similarly, the adhesive 26 is applied on the connection electrode 23 on the back surface side of the solar cell 10. The wiring material 27 is placed through the wire, and it is pressed lightly so as not to separate from each other and heated to an appropriate temperature (S12).

  FIG. 3 is a diagram showing the solar cell module in a state where the wiring members 25 and 27 are arranged on the connection electrodes 20 and 23 via the adhesives 24 and 26, and FIG. (B) is a side view.

  The wiring members 25 and 27 are thin plates made of a metal conductive material such as copper. Instead of a thin plate, a stranded wire can be used. As the conductive material, in addition to copper, silver, aluminum, nickel, tin, gold, or an alloy thereof can be used. The wiring member 25 is preferably arranged so as to cover the connection electrode 20 along the arrangement direction of the connection electrode 20 on the light receiving surface side of the solar cell 10, and the width of the wiring member 25 is set to be the connection electrode 20. It is better to set it to be the same as or slightly thicker. Similarly, the width of the wiring member 27 on the back surface side may be set to be the same as or slightly thicker than the width of the connection electrode 23 on the back surface side.

  The adhesive 24 is disposed between the connection electrode 20 and the wiring member 25 on the light receiving surface side, electrically connects the connection electrode 20 and the wiring member 25, and the light receiving surface side of the solar cell 10 and the wiring member. 25 is used for mechanically fixing. Similarly, the adhesive 26 is disposed between the connection electrode 23 on the back surface side and the wiring material 27, electrically connects the connection electrode 23 and the wiring material 27, and connects the back surface side of the solar cell 10 and the wiring. Used to mechanically fix the material 27.

As the adhesives 24 and 26, thermosetting resin adhesives such as acrylic, highly flexible polyurethane, or epoxy can be used. The curing temperature θ _H of the adhesives 24 and 26 is selected between about 130 ° C. and 300 ° C. from the heat resistance of the solar cell 10 and the like.

  The adhesives 24 and 26 include conductive particles. As the conductive particles, nickel, silver, nickel with gold coating, copper with tin plating, or the like can be used. As the adhesives 24 and 26, insulating resin adhesives that do not contain conductive particles can also be used. In this case, one or both of the facing surfaces of the wiring members 25 and 27 or the connecting electrodes 20 and 23 are made uneven so that the wiring member 27 and the connecting electrode 20 are connected. Resin is appropriately removed from between the electrodes 23 to establish electrical connection. The light receiving surface side is bonded by an adhesive force between the facing surfaces of the wiring member 25 and the connection electrode 20 and an adhesive force by a resin fillet formed on the light receiving surface of the solar cell 10 and the side surface of the wiring member 25. Similarly, also on the back surface side, adhesion is caused by the adhesive force between the facing surfaces of the wiring member 27 and the connection electrode 23 and the adhesive force by the resin fillet formed on the light receiving surface of the solar cell 10 and the side surface of the wiring member 27. Is done.

  Returning to FIG. 1 again, when the wiring material placement process is completed, the crimping process is performed. In the crimping process, a crimping tool designed so that a low crimping pressure is applied to the end of the solar cell 10 on which the wiring members 25 and 27 are arranged is set (S13), and the crimping tool is pressed to a predetermined pressing pressure. This is a process of curing the adhesive by pressing at a predetermined temperature (S14).

  Although the positional relationship between the end portion and the center portion is shown in FIG. 3, the end portion is a region on the end face side of the solar cell 10 in the longitudinal direction of the wiring members 25 and 27. The end region can be determined in consideration of the contribution of the photogenerated carriers of the solar cell 10 to the current collection. For example, with respect to the total number of finger electrodes, a region having a predetermined number counted from the end face of the solar cell 10 can be set as the end. Or it can be set as the area | region of the predetermined width inside from the end surface of the solar cell 10. FIG. As an example, about 20 mm can be made into an edge part from the end surface of the solar cell 10 inside. This number is an example and can be changed according to the specifications of the solar cell 10.

  FIG. 4 is a diagram illustrating a state where the crimping process is performed using the crimping tool. The crimping tool includes a lower tool 30 and an upper tool 31 that moves up and down relatively with respect to the lower tool 30. The solar cell on which the wiring material is arranged is placed on the lower tool 30, and the upper tool 31 is moved upward with respect to the lower tool 30. This is a device that lowers the tool 31 and applies a predetermined pressing force F to the upper tool 31 against the lower tool 30. Moreover, the heating parts 32 and 33 are arrange | positioned at the lower tool 30 and the upper tool 31, respectively, and the solar cell with which the wiring material is arrange | positioned is heated by predetermined heating temperature. As the heating units 32 and 33, a resistance wire heater, a heating lamp, a heating air supply device, or the like can be used. Thus, the crimping tool is a pressure heating device.

  The lower tool 30 and the upper tool 31 have a convex shape in which the central portion protrudes from the end portion on the crimping surface. In FIG. 4, a gap is generated between the end of the lower tool 30 and the wiring member 27 in a part surrounded by a broken-line circle, and a gap is generated between the end of the upper tool 31 and the wiring member 25. Showed this. Note that the size of the gap in FIG. 4 is exaggerated for explanation. The shape of the central portion protruding from the end portion is such that the central portion is flat and the gap gradually increases from the flat portion toward the end surface. The degree of increase in the gap is preferably determined experimentally. Depending on the experimental result, for example, the gap may be increased linearly toward the end face, or may be increased in a curved manner.

  In FIG. 4, one lower tool 30 and one upper tool 31 are shown, but as shown in FIGS. 2 and 3, there are three wiring members 25 and 27 in parallel. Accordingly, three lower tools 30 can be provided in parallel, and three upper tools 31 can be provided in parallel. In this case, one lower tool and one upper tool that face each other with one wiring member interposed therebetween form a pair. For example, three pairs may be integrated and lifted relatively.

  The heating temperature θ in the pressure bonding process is set to be equal to or higher than the curing temperature of the adhesives 24 and 26. θ is set to a higher temperature as the heating time determined by the cycle time of the crimping process is shorter. For example, when the heating time can be taken sufficiently long, θ can be set as the curing temperature, but when the heating time is several seconds, θ is set to a temperature higher than the curing temperature.

The pressing force F is set so that the pressure bonding pressure P is 0.1 MPa to 0.2 MPa. Here, the pressing force F is a load force applied from the upper tool 31 to the lower tool 30, and has a dimension of N (Newton). The pressure P is a force per unit area having a dimension of N / m ² and applied to the surface where the lower tool 30 and the wiring member 27 are in contact and the surface where the upper tool 31 and the wiring member 27 are in contact.

  When a solar cell in which a wiring material is arranged is sandwiched between a lower tool 30 and a upper tool 31 having a convex shape projecting from the center portion rather than the end portion, and a pressing force F is applied to the upper tool 31 against the lower tool 30, The amount of deformation in the thickness direction is large at the center of the solar cell, and the amount of deformation in the thickness direction is small at the end. The amount of deformation is the total thickness from the wiring material 25 on the light receiving surface side to the wiring material 27 on the back surface side. In the central portion where the amount of deformation is large, a large compressive stress is applied in the thickness direction, but the compressive stress received at the end portion where the amount of deformation is small is small. This compressive stress corresponds to the pressure P.

FIG. 5 shows the distribution of the pressure P. The horizontal axis is the position of the solar cell along the longitudinal direction of the wiring material, and the vertical axis is the pressure P. In the central part, P = P _{0 is} a constant value, and the pressure P is gradually reduced from P ₀ toward the end face of the solar cell from the boundary between the central part and the end part.

  Returning to FIG. 1 again, when the crimping process is completed, the remaining process for obtaining a solar cell module is performed (S15). Here, the solar cell module subjected to the crimping process is positioned between the light-receiving surface side protection member and the back-surface side protection member, and the filler is provided between the light-receiving surface-side protection member and the back surface-side protection member. Place. Frames are arranged at the ends of the light receiving surface side protective member and the back surface side protective member.

  A transparent plate or film is used as the protective member on the light receiving surface side. For example, a translucent member such as a glass plate, a resin plate, or a resin film can be used. As the protective member on the back surface side, the same protective member as that on the light receiving surface side can be used. In the case of a solar cell module having a structure that does not require light reception from the back side, an opaque plate or film can be used as the protective member on the back side. For example, a laminated film such as a resin film having an aluminum foil inside can be used. As the filler, EVA, EEA, PVB, silicone resin, urethane resin, acrylic resin, epoxy resin, or the like can be used. Thus, a solar cell module is manufactured.

  In the above, the lower tool 30 and the upper tool 31 having a convex shape projecting from the center part are used rather than the end part in order to make the pressure pressure at the end part lower than the pressure stress at the center part, but as shown in FIG. The thickness of the end portions of the connection electrodes 34 and 35 may be made thinner than the thickness of the central portion. In this case, the connection electrodes 34 and 35 can be crimped using the lower tool 36 and the upper tool 37 whose entire crimping surface is flat. Thereby, the crimping surfaces of the lower tool 36 and the upper tool 37 can be flattened from the center to the end, and a crimping tool common to the prior art can be used.

  In FIG. 6, a gap is formed between the end portion of the connection electrode 35 on the back surface side and the wiring member 27 in a portion surrounded by a broken-line circle, and the end portion of the connection electrode 34 on the light receiving surface side and the wiring member 25. This was shown by the gap between the two. As in FIG. 4, the size of the gap is exaggerated for the sake of explanation. In the shape in which the thickness of the end portion is thinner than the thickness of the central portion, the thickness of the central portion is constant, and the thickness gradually decreases from the central portion toward the end surface. The degree of thickness reduction should be determined experimentally. Depending on the experimental result, for example, the thickness may be decreased linearly toward the end face, or may be decreased in a curved manner.

  As shown in FIG. 5, the pressure at the end of the solar cell 10 is lower than the pressure at the center so that the end of the solar cell 10 is an important part for the connection between the solar cell 10 and the wiring members 25 and 27. This is because the connection between the solar cell 10 and the connection electrodes 20 and 23 is suppressed and the connection is secured.

  In order to explain the peeling related to the connection between the solar cell 10 and the wiring members 25 and 27, a sectional view on the light receiving surface side of the solar cell 10 is shown in FIG. There are three places where peeling can occur between the solar cell 10 and the wiring member 25. The first is peeling of the first junction between the transparent conductive film 12 on the photoelectric conversion unit 11 and the connection electrode 20. In FIG. 7, the first junction is shown as (12-20). The second is peeling between electrodes between the connection electrodes 20 itself. In FIG. 7, this portion is shown as (20-20). The third is peeling of the second joint between the connection electrode 20 and the wiring member 25 via the adhesive 24. In FIG. 7, the second junction is shown as (20-25). In addition to this, the boundary between the photoelectric conversion unit 11 and the transparent conductive film 12 and the separation between the wiring materials between the wiring material 25 itself can be considered, but these hardly cause the separation.

  Here, when the crimping | compression-bonding process of a wiring material is performed using the crimping | compression-bonding tool with a flat crimping surface used by a prior art, the crimping pressure of the center part and end part of the solar cell 10 becomes the same. Here, when the pressure bonding stress is too high to receive the pressure bonding stress in the first bonding, peeling tends to occur at the first bonding portion. In particular, when a sintered conductive paste having a network structure is used for the connection electrode 20, the strength of the connection electrode 20 itself is increased because the bonding strength of the network structure is strong. Therefore, if the adhesive strength of the first joint is relatively weak and the pressure bonding stress is too high, the possibility that peeling may occur in the first joint increases.

  Since the first junction is an electrical junction for extracting current from the solar cell 10, if peeling occurs here, it is a problem even if the connection electrode 20 itself and the second junction are strong. Therefore, prevention of peeling of the first joint is important. In particular, in the solar cell module, the wiring member 25 is bent between the adjacent solar cells 10, and is generated in the wiring member 25 at an adhesive portion with the wiring member 25 near the end of the solar cell 10 near the bent portion. Stress is often concentrated. Therefore, it is highly necessary to suppress peeling at the first junction at the end of the solar cell 10.

  The relationship between the adhesive strength of the first bonding and the strength of the fusion aggregation of the conductive particles in the connection electrodes 20 and 23 can be confirmed by the occurrence rate of peeling. FIG. 8 is a diagram showing the rate of occurrence of peeling in the first bonding when the pressure bonding pressure distribution is shown in FIG. The horizontal axis is the same as that in FIG. 5, the position of the solar cell along the longitudinal direction of the wiring members 25 and 27, and the vertical axis is the (12-20) mode peeling rate. The (12-20) mode peeling rate refers to the location where peeling occurred in the peeling test of the solar cell module, and peeling occurred at the location of (12-20) which is the first bonding described in FIG. It is a value obtained by dividing the number by the total number of peeling.

  As shown in FIG. 8, in the solar cell module in the present embodiment, the (12-20) mode peeling rate is lower than the central portion at the end of solar cell 10. In the crimping process of the wiring members 25 and 27, when the crimping pressure at the end of the solar cell 10 is lower than the crimping pressure at the center, the strength of the fusion aggregation of the conductive particles at the connection electrodes 20 and 23 is at the center at the end. Become weaker. Therefore, at the end portion of the solar cell 10, the adhesive strength of the first bonding is relatively stronger than the strength of the fusion aggregation of the conductive particles in the connection electrodes 20 and 23. As a result, peeling at the connection electrodes 20 and 23 is more likely to occur at the end portion of the solar cell 10 than at the first bonding, and the (12-20) mode peeling rate at the end portion of the solar cell 10 is the central portion. Lower than Thus, by making the pressure-bonding pressure at the end of the solar cell 10 lower than the pressure-bonding pressure at the center, the peeling between the solar cell 10 and the connection electrodes 20, 23 is greatly reduced at the end of the solar cell 10. Can be suppressed.

  9 and 10 are diagrams for explaining the effect of the above-described pressure bonding pressure. These figures are diagrams showing the peeling at the end of the solar cell in the result of the peeling test of the solar cell module, and FIG. 9 is a comparative example in which the crimping pressure at the end is the same as the crimping pressure at the center. FIG. 7 shows a case where the crimping stress distribution shown in FIG. 5 is used.

  In FIG. 9 of the comparative example, peeling occurs at the junction between the transparent conductive film on the photoelectric conversion portion and the connection electrode, and the surface 40 where the transparent conductive film of the photoelectric conversion portion of the solar cell is exposed appears, and the adhesive is A partially lost layer 42 and traces 41 of connection electrodes were visible.

  If the pressure stress at the end is lower than that at the center, peeling does not occur at the joint between the transparent conductive film on the photoelectric conversion portion and the connection electrode, and the conductive particles are fused and aggregated at the connection electrode. Peeling occurred in the part where it was. In FIG. 10, the adhesive layer 43 is visible, and below that, the layer 44 that has been peeled off by the fused aggregate layer of the connecting electrode but remains in the transparent conductive film is shown.

  Thus, by making the pressure-bonding pressure at the end of the solar cell lower than the pressure-bonding pressure at the center, the solar cell is connected to the solar cell at the end of the solar cell, which is an important part for the connection between the solar cell and the wiring material. Connection between the electrodes can be secured.

  DESCRIPTION OF SYMBOLS 10 Solar cell, 11 Photoelectric conversion part, 12, 13 Transparent conductive film, 20, 23, 34, 35 Connection electrode, 21 Spherical powder, 24, 26 Adhesive, 25, 27 Wiring material, 30, 36 Lower tool, 31 , 37 Upper tool, 32, 33 Heating part, 40 Exposed surface of transparent conductive film, 41 Trace of connecting electrode, 42 Layer partially lost adhesive, 43 Adhesive layer, 44 Melting of connecting electrode A layer that remains on the transparent conductive film in an aggregated layer.

Claims (3)

Arrange the wiring material through the adhesive to the connection electrode of the solar cell,
Pressing a crimping tool at a predetermined crimping pressure against the solar cell on which the wiring material is disposed, and curing the adhesive by heating to a curing temperature or higher,
The method for producing a solar cell module, wherein the predetermined pressure of the crimping tool is such that the pressure at the end of the solar cell along the longitudinal direction of the wiring member is lower than the pressure at the center of the solar cell. Because
The method for manufacturing a solar cell module, wherein the connection electrode is an electrode in which conductive particles are fused to each other by heating to form a network structure. In the manufacturing method of the solar cell module according to claim 1 ,
The connection electrode includes a resin and is formed to have a longitudinal direction;
A method for manufacturing a solar cell module, wherein the peel strength of the connection electrode itself is weaker than that of a central portion at an end portion in the longitudinal direction of the connection electrode. A solar cell comprising a connecting electrode having a longitudinal direction;
A wiring material connected to the connection electrode via an adhesive;
With
The connection electrode includes a plurality of conductive particles fused together to form a network structure along the entire length direction, and a resin.
The peel strength of the connection electrode itself is weaker than the central portion at the longitudinal end of the connection electrode,
The solar cell module in which the adhesive strength between the connection electrode and the solar cell is stronger than the peel strength of the connection electrode itself at the end of the solar cell along the longitudinal direction of the wiring member .

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